Portable dictation machine



Sept. 13, 1960 D. F. BALMER ETAL 2,952,747 f i Sept 13, 1950 D. F. BALMER ETAL 2,952,747

PORTABLE DICTATION MACHINE l0 Sheets-Sheet 2 Filed Aug. 24, 1956 INVENTORS DONHLD F. BHL MER WILL/HM H. LYON By FRE/VK E, QU/ves EDM/HRD PI JOHNSON HrToRA/EY Sept. 13, 1960 D. F. BALMER ETAL 2,952,747

PORTABLE DICTATION MACHINE 10 Sheets-Sheet 5 Filed Aug. 24, 1956 FTTOR/ VEY D. F. BALMER ET AL 2,952,747

PORTABLE DICTATION MACHINE Sept. 13, 1960 lO Sheets-Sheet 4 Filed Aug. 24, 1956 FTTORNEY Sept- 13, 1960 D. F. BALMER ET AL 2,952,747

PORTABLE DICTATION MACHINE l0 Sheets-Sheet 6 Filed Aug. 24, 195e L\ QQ l. INVENTORS DONHLD F. BHLMER WILL/FIM H, LYON By FRI-'NVK E. RUNGE sow/@Ro P, JOHNSON HTTORNEY Sept. 13, 1960 D. F. BALMER ETAL PORTABLE DICTATION MACHINE Filed Aug. 24, 1956 l0 Sheets-Sheet 7 INVENTORS DONHLD vF. BHLMER WILL/HM Hl LYON BY FRF/VK E, RUNCE EDM/HRD P. JOHNS 0N Sept 13, 1950 D. F. BALMER ETAL 2,952,747

PORTABLE: DICTATION MACHINE 10 Sheets-Sheet 8 Filed Aug. 24, 1956 E O mMww mmYNH NBLUO vl h .H,RJ E NF ,R N I MED on mmKR m Nmmw H WWE:

SP- 13, 1960 D. F. BALMER ET AL 2,952,747

PORTABLE DICTATION MACHINE lO Sheets-Sheet 9 Filed Aug. 24, 1956 Q l EEE Sept. 13, 1960 D. F. BALMER ETAL 95234? PORTABLE DICTATION MCHINE 10 Sheets-Sheet 10 Filed Aug. 24, 1956 KQM.

United States Patent i? ce PORTABLE DICTATION MACHINE Donald F. Balmer, East River, William H. Lyon, Orange, Frank E. Runge, Branford, and Edward P. Johnson, East Haven, Conn., assignors to The Soundscriber Corporation, New Haven, Conn., a corporation of Connecticut Filed Aug. 24, 1956, Ser. N0. 606,128

18 Claims. (Cl. 179-10031) This invention -relates to sound recording and reproducing machines, :and more particularly to a dictating machine of the type wherein a thin plastic disk is embossed by a recording head which forms a spiral sound track upon the surface of the disk.

One object of this invention is to provide a dictating machine of the above nature, which is self-contained in a lightweight small sized case.

Another object is to provide ya dictating machine of the above nature, having novel feeding means `for the recording head which enables the recording of the sound track to be temporarily interrupted and later resumed Without destroying the continuity of the recording.

A further object is to provide means to produce an audible warning signal for dictating machines of the above nature to indicate when the controls are improperly set for the recording operation, so as to warn the user against attempting the record dictation under such conditions.

A further object is to provide a device of the above nature which will be simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, ornamental in appearance, and very eiiicient and durable 1n use.

With these and other objects in view, there has been illustrated in the accompanying drawings one form in which the invention may conveniently be embodied in practice.

In the drawings,

Fig. 1 represents a top view of one form of lightweight portable dictating machine embodying the present invention.

Fig. 2 is a side view of the same.

Fig. 3 is a -top View of the same with the front and back covers in open position, and with a microphone and power cable assembled ready for use.

Fig. 4 is a horizontal sectional view of the dictating machine, on a somewhat enlarged scale, taken on the line 4 4 of Fig. 2.

Fig. 5 is a vertical cross-sectional view of the same taken on the line 5 5 of Fig. 1.

Fig. 6 is a vertical cross-sectional view of the taken on the line 6 6 of Fig. 1.

Fig. 7 is a horizontal cross-section, taken on the line 7-7 of Fig. 5 looking upwardly.

Fig. 8 is a fragmentary vertical cross-section, on a still larger scale, taken on the line 8 8-of Fig. 7.

same,

2,952,74? Patented Sept. 13, 1960 Fig. 14 is a fragmentary vertical cross-section, taken on the line 14-14 of Fig. 4.

Fig. 15 is a fragmentary vertical cross-section, on an enlarged scale, taken on the line 15--15 of Fig. 13.

Fig. 16 is a fragmentary top view, showing the mounting for the driving motor.

Fig. 17 is a fragmentary vertical cross-section, taken on the line 17 17 of Fig. 16.

Fig. 18 is -a fragmetnary vertical cross-section on an enlarged scale, taken on the line 18-18 of Fig. 17.

Fig. 19 is a fragmentary vertical cross-section, taken on the line 19-19 of Fig. 4, and j Fig. 20 is a schematic diagram of the electrical cir-Y cuits.

' Referring now to the drawings, in which like reference numerals denote corresponding parts throughout the several views, the numeral 10 indicates a chassis which supports a motor 13, a turntable 12, a recording arm 14, a playback arm 15, and a recording disk 16. Attached to this mechanical assembly is an amplifier assembly 17, both assemblies being housed in a cabinet 11 which consists of a lower section 18 and an upper section 19 rigidly secured to the lower half 1S.

A rear compartment cover 20 is joined to the upper section 19 of the cabinet 11 by a hinge 23 to provide a compartment designed =to contain a microphone 28, its associated cable 29, and a power cable 30.

The rear cover is secured in place by a releasable snap lock 25.

A detachable front cover 21 is also provided to pr tect the operating controls of the equipment, said front cover 21 being held in place by a manually operated releasable cover lock 22. A decorative band 24 forms au offset flange to receive the rear edge of the cover 21. Y A pivoted handle 26 is attached to the bottom section 18 of the cabinet by button fasteners 27.

The recording larm 14 is located on the right-hand side of the machine, and consists of a recording arm shell 31, a downward extension 36, land a knife edge 37, which is attached to the extension 36; (See Figs. 6, 8 and 9.)

A recording head 45 (Fig. 9) is mounted by means of a pivot pin 46 inside the recording shell 31. Y Y I The necessary recording pressure is applied to a Vstylus 39 by a coiled spring 47. Adjustment of the stylus` pressure on the record may bermade manually by a horizontal screw 48 and an associated adjustment slide bracket 49. Y The recording arm assembly is attached by means of a flexible strip hinge 32 secured to a recording arm bracket 35 (Fig. 6), which is secured to a vertical stanchion 34 attached to the chassis 10 by means of a pivot pin 33. 1

Downward pressure is applied to the arm 14 and the i knife edge 37 by means of a horizontal coil spring 57 Fig. 9 is a fragmentary vertical cross-section, taken on the line 9 9 of Fig. 8. i Fig. 10 is a fragmentary sectional view of the same, showing the indexing mechanism for the recording head.

Fig. 11 is a fragmentary vertical section, taken on the line 11 11 of Fig. 8, of the mechanism shown in Fig. 10,

which holds the knife edge 37 in firm contact with a horizontal lead screw 63 (Fig. 8) during the recording process.

During playback, the recording arm 14 Will be raised in sucha manner that the recording stylus 39 will be lifted from the recording disk 16, and the knife edge 37 will be lifted from the. lead screw 63. This lifting ispro duced by a U-shaped lifting bar (Figs. 8 and 9) which is pivotally supported at each side at the ends of the lead screw 63. The lifting bar 85 has a forwardly extending arm at one side which is operated by a substantially vertical Talk-Listen button 88 located at the front of the chassis 10 and is pivotally connected to said arm of said bar by a pin 87. When the Talk-Listen button 88 is depressed and pushed rearwardly, a notch 93 (Figs. 6 and 9) on said button 88 will move under the edge of theAchassis 10 and hold said button in a depressed posi tion and will maintain the machine set for playback operation. Y

. 'V :3V The .rear yend .of .the .lifting .bar .85 .lies substantially parallel with the lead screw ..63 and contacts a frictional nylon strip 41 (Figs. 9 and -1'0) attached to the underside of .fa flexible frecording'hrm lifting Vfinger :.40 secured.' to the downward extension 36. 'Ihenger 40, when :lifted by the .lifting ibar 85, :sers/tes to Vraise the recording :arm shell 31 andthe extension 3.6 :until-astop bumper .43 on the .recording arm .14 contacts arfrictional nylon strip .42 attached to the underside of the .chassis r (Hg. 10).. When this .point is reached, further "motion of the lifting bar 85 merely bends the lifting `finger .40 and squeezes lthe depending arm extension l3.6 :between the chassis 10 and the .lifting bar 85 .so as to hold `the recording .arm 14 rmly .in :raisedY position. The arm14 may, however, be swung horizontally over .its .operating range by .exerting pressure :manually .onone side .or -the other, vand the nylon strips 41 and 4Z provide smooth friction surfaces for lthis-action. The .pressure with which .the .arm v14.s gripped can be varied by turning .an arm lifting adjustmentfscrew 44 bymeans of .a wrench (Fig. 9,). A recording arm level adjustment screw .50 is also .provided -.to vary the height `4of .the :recording arm shell 31 =with reference :to the knife edge.37 (Fig. .4).

. The v.turntable 12 .is rim-driven -by amechanism located atthe'rear of the .cabinet and will Vbe described later. A Itapered square rounded pin '58 is'located Lin the .center of .the turntable 12 and .is adapted .to .lit within a similar square hole in -the record .disk 16. A .thin yieldable pad 59, vpreferably comprising a thin sheetof Vinylite (Fig. 8) is placed on top of the turntable '12 and provides la support for fthe Adisk j16 lduring recording. .It also vserves as a relatively soft surface for perventing injury to the stylus 39 if .the latter should .accidentallybe dropped on the turntable when -no record disk is `in place. l

The turntable 12 is attached to a -Vertical vspindle -60 having a worm section 62 (Fig. 14). The turntable spindle 60 is Vsupported by bearings in Ya gear box .61 'having a vcover cap 71. VV"Ihe lead screw 163 lis supported @in the same gear box 61 and is `mec'zhanically connected to the spindle worm-section621by adriven gear.64, which turns the lead screw .shaft 63, and is he'ld firmly 1in positionbetween :a friction Iwasher 65 and a friction `washer 66 (Fig 8). The frictionwasher -65 is held firmly in `'contact with a collar 70, which is secured to the lead .screw 63. A pressure Washer 67 -is held firmly -against the Ifriction wash`er`66'by a'pair of Yspring washers68 and a-tightening nut 69.

'The Washers 65, 66, 67 and 68 comprise a Vclutch assembly, lthe lcompression of :which can be varied'by adjusting the nut 69. y

fIt will be understood thatthellead screw63 turns-when the -turntable 1'2 is driven, and drives the recording arm .as ,previously described. At .the same time, a latch pawl 82 will engage the teeth of the ratchet wheel 74 and stop it from rotating. (See Figs. 9 and l0.) The rotation of the lead screw 63 clockwise (-as viewed in Figs. 9 and 10), however, will not beY stopped until the pin 7S has swung approximately fortyave degrees and has come into engagement with Vthe istop 77. At thisv point, the lead screw ,63 will stop rotating, and the drive gear 64 will start -to slip on its shaft. 'The friction causedby slipping loads the turntable 12 andthe motor 'driving it, ;by exactly .the .same .amount asthe recording stylus 39 does during the recording process. This results .in an .equal load on the turntable during both recording and playback, and insures that -the speed during .both `of these functions will be identical.

When the arm 14 is moved to the outside of the disk (toward the right, as seen in Fig. 8) for starting a new record, a bumper 438 attached .to he knife edge'37 Will contact a face .cam 72, .secured firmly .to .the lead :screw 63 by Ia `setscrew "73, zandsstop thearm 14 .exactly at a predetermined point. .The cam 72 has .an inclined .face ground to exactly match the p'itch .of the threads .on fthe lead screw 63`in Aorder .fto :insure that the knife .edge .137

will stop directly labove .the Vebottomofa thread :on the lead screw 63. Consequently, no matter .in whatzposition the lead Ascrew 63 stops, the knifeedge'37 will .always .be directly over the bottom of a QV. this insures that 'the recording arm 14 .will lstart ffeeding 'immediatelyyvhenthe knife edge is 'loweredfupon .the lead .screw 263, at the same time that .the ratchet 7.4 is .released vby the latch Vpawl 82, to permit the lead Vscrew 63 .to start turning. This 1arrangement is necessary to prevent a VYdelayed Vstart 4of `the feeding .of the recording arm 14, which might cause I.the latter-to record several ygrooves lbeforc normal feed begins.

An index lever 79 (Fig. 8'.)"-is swingablyttached @with respect to the outer end of the lead screw 63, andcarries a pivoted pawl 80 (see Figs'. ill and i12), which iis designed to engage'the teeth fof ther-ratchet wheel '74Pwhen the lever 79 iis manually operated. The operation-ofthe index lever '7-9 overdrives the lead screw 63 through the ratchet Wheel 74 by slipping the clutch washers 6'5 V'and 66. This Vadvances the recording arm 14 lrapidly, and produces Va yspiral of greater than 'normal pitch on the disk 16, Vlea-ving a visible space between groove formations, which is used to indicate a correction inthe -dictated material. Moreover, the index lever 79 Amay be pushed twice to produce a double space to `indicate 'the end of a letter, lin .accordance :with the Ivisible indexing 414 through the knife edge 37 when the latter is lowered into engagement with Athe teeth of said lead screw. At the outer extremity ofthe lead screw 63 provision is made of Ya ratchet wheel 74, vwhich-is freely mounted on the -lead screw 63 vand'has its motion limited by `a cross pin 75. (See 'Figs.9-12)' A pair of radial shoulder stops 77 and 78, which are a part of the ratchet wheel 74, jengage the pin 75 and limit the rotation of 'said ratchet wheel 74 on its shaft. The stops ;77 and 78 are angularly spaced by approximately forty-five degrees.. By means of this construction, the lead screw 6 3may turn in its operating direction (clockwise, as viewed in Fig. 9) -through a forty-tive degree range before vit Ais locked to the ratchet wheel 74. As more fully describedhereinbelow, the lead screw 63 will thus be advanced by an amount corresponding to slightly more than one groove on the record disk, thus providing a vprotective space between Vst lccessive recordings. A curved over-travel coil spring '76 urges the ratchet wheel y74 in one direction so .that the pin 75 normally rests against the stop 78.

`When the machinefis changed from -recording to Y P layback, the recording arm `14 and the knife edge 37 will be raised and clamped firmly in their upper position system disclosed and claimed 'in Patent No. Y2,611,620 dated September 16, 1952, to Runge, Record Marker for 'Dictating Machiuesi i Y Y A coiled spring 81 connected to the index llever '79 serves kto return said lever 5to its Vnormal position shown .in Figs. 6,1171, l2. Y v Y 'The latch pawl 82 is operated Aby a bell crank lever 91 (Fig. 9) having an Ainclined slot 91a, to'receivean operating pin 86 attached to the armlifting bar `85. A spring 92 serves to return the bell -crank lever 91 toits forward positionY (as shown in Fig. 9 and lifts the talk-listen button 88 up to its recording position. However, when the button 88 -is pressed down and locked to the chassis 10 by the notch 93, the pin "86 forces lthe bell `crank lever 91 backwardly (towardthe right 'hand side in Fig. 19) and causes the latch 8210 engagewith the ratchet wheel 74. In swinging on its pivot 9.0, the hel-l crank lever191 will also operate the selector switch89 which selects .between recording or playback conditions of the an'lplifier,

The vlatch 82 is connected ,tor the bell crank lever 9'1"by a cross pin 84 loosely `received'in a slot 18441. Thus if the latch `82'should accidentally Vstrike the top of a toothV on the ratchet wheel 74, an overtravel spring .83 will take up the vmotion of the Y.bell kcrank lever .91 and .pfl'mt .it to complete `its normal -cycle.

topof the recording arm-bracket '35, is ,an angular end-of-record signal arm 54 (see Figs. 4, 5, 6 and '8) having a exible reed 55 attached at the left hand end thereof. Thus, as the recording arm 14 moves toward the inner portion of the disk 16, the signal reed 55 will move close to the axis of a pulley 112 carrying a pin 56 which projects upwardly and repeatedly strikes the signal reed 55 when the recording arm 14 Areaches the end of its recording range. This produces an audible sound to indicate to the dictator that the disk 16 is nearly recorded. A U-shaped bridge 53 is attached to both sides of the chassis and extends over the arms 14 and and the turntable 12. (See Figs. 4, 5, 6, 8 and 9.) Attached to the right hand part of the bridge 53 is a forwardly-extending pointer 52 which is located in proximity Ito a curved log scale 51 provided on the top of the recording arm 14. (See Figs. 3 and 4.)

The motor \13 is rmly held by a mounting bracket 94 (see Figs. 16, 17 and 18), and at three points on said bracket soft rubber grommets 96 are inserted, which grommets iit over three studs 95 which are rmly attached to the chassis 10. A conical portion 111a of the grommet seat 111 located on the studs 95 center each grommet 96 and leave it free to absorb motor vibration. A nut 110 holds the grommet 96 in place, and prevents itfrom moving upwardly when the machine is carried in other than a level position. A small pulley 97 (Fig. 4) is attached to ya motor shaft 97a, which carries a notched fau blade 98 for cooling the motor 13. A spindle 11S iirmly attached to the chassis 10 between the motor 13 and the turntable 12 supports a pulley 1,12 and its associated pulley shaft 113. (See Figs. 4, 7, 13 and 15.) A exi'b-le rubber -belt 116 connects the pulley 1'12 with the motor pulley 97.

The flexibility of the belt 1\16 insulates the vibration of the motor from the other parts of the driving system.

A coil 4spring 99 between the motor 13 vand the chassis 10 compensates for the pull of the belt 116 and permits the three grommets 96 to remain centered on their conical supports 111a (Fig. 18). An idler pulley yi117 (Fig. 4) attached to the motor 13 by a bracket 1'18 rides against the belt 116 and takes up its slack.

A rubber tired idler wheel 119 (Fig. 4) transmits the rotation of the driving surface 114 on the shaft 113 to the edge of the turntable 12. This idler wheel 119 is supported by a shaft 120 -fixed to a slide plate 121 (Figs. 7, 13 and `l5) sandwiched between the chassis 10 and a bracket 122 mounted under the chassis 10. A11 armature 125 (Figs. 7 and 13) of an electro-magnet 123 is connected to the shaft 120 through an arm 124 and a wire spring link 126 (Fig. 15). Thus, when the electro-magnet 123 is energized, the rubber drive wheel 119 will be pulled into contact with the turntable 12 and the end driving surface 114 of the pulley shaft 113 will rotate said turntable. A coil spring 127 serves to disengage the rubber tired wheel 119 from the turntable 12 when the electro-magnet 123 is deenergized. The playback arm 15 (Figs. 4 and 5) is located on the left-hand side of the machine chas-sis 10 and is supported on a horizontal pivot pin 131 attached to a mounting block 130 which, in turn is supported by a vertical pivot pin 129 attached to the chassis 10. The arm 15 is counterbalanced by a rear weight 128 (Figs. v4 and 5).

Downward pressure is exerted on the playback arm 15 by a coil spring 132, and a playback head 141 (Fig. 5) is securely mounted in the forward part of the arm 15. A playback stylus 140, which is secured to the head 141, is located in such a way that it follows freely the grooves recorded on the disk 16. A ilat leaf spring 133 (Fig. 19) attached to the bridge 53 is located above an arm support cone 134 which is attached to` the bridge 53 by a block 135. The combination of the cone 134 and the spring 133 provides a lock for the arm 15, when it is not in use. The cone 134 facilitates `the sliding of the arm 15 downwardly and dropsvthe stylus atthe proper starting point on thev disk record for playback. lf

A- switch actuator 136 (Fig. 19), is attachedtojth arm 15 and projects below the chassis 10. Y This actuator 136 opens a leaf switch 137 when the playback arm is' in the rest position. The switch 137 controls an alarm circuit that warns the operator when the machine is not in recording position. The lleaf switch 137 is attached to and forms a part of the amplier assembly 17.

A volume control knob 138 (Figs. 4 and 13) is located on the forward left-hand corner of the chassis 10. log scale 139 is attached to the bridge 53 and is located above the playback arm 15 in proximity to an `indicating mark 15a thereon. A i

Circuit diagram A diagram of the electrical circuits is shown in Figi 20 of the drawings. Thus, the power cable 30 which enters the back of the lower cabinet section 1S (as shown in Fig. 3) has one lead 142 which forms va com# mon connection, and is connected to the chassis 10 byY a capacitor 143. The other connection 144 from the power cable 30 goes directly to the main switch 138a which is manually operated by the volume control knob 138, together with the volume control resistor 138b, in a manner well known in the art,

Closing the switch 138a will connectV the ield of the motor 13 directly across the source of energy represented by the leads 142 and `144, and also establishes a circuit with a'voltage dropping resistor 145, connected to a rectifier 146, which in turn supplies the positive plate potential for the vacuum tubes V-1 and V2. The electro-magnet 123 is also connected between the posi` tive side of the rectifier 146 and the common connection 142, and its operation is controlled by a manually operable switch 1 47 which is positioned in the casing of the microphone 28, as shown in Fig. 3. *Y Y Y v A pair of external leads`1|48 may alsobe provided for connection with a foot pedal switch 149 or other external switch means, if desired. i The selector switch 89 comprises four ganged single pole double throw switches indicated at 89a, 89h, 89e, and 89d in Fig. 20, said switches being shown iri'this ligure in recording position. i t

One side of the microphone'ZS is connected to the common connection V142, while the other side of the microphone is connected'to themovable'contact of 'the switch 89a, and to one of the fixed contacts of-the switchv89c. In fthe recording position, a circuit will be established through the switch 89a with a contact of switches 89b and 89d, the latter two switches being so arranged that in the recording position a circuit will be established through fthe switches 89a and 89B from the microphone 28 -to the first controlA grid of the vacuum tube V41.

VThe recording head 45 is energized by a transformer 150 which is connected inthe output circuit of the vacuum tube V-2, and the connection between the transeV former 150 and the recording head 45 is controlled by the switch 89d. When'the switch `89d is in the .playback position, -it connects vm'th a wire which leadsto the fixed contacts of switches 89a and 89b, at which time therecording section of said switches will be inactive? One side of the pickup 1'41 is connected to the common connection 142, While the other side is connected through the variable resistor 138]; to a nxed contact of the switch 89a, so that -when this latter switch is in its playback position, the pickup 141 will be connected tothe control grid of the vacuum tube V-l, instead of lthe microphone 28. When this shift is made by the selector switch 89, the microphone 28 will then be connected,`b'y the shifting of the switch 89a to its playback position',V to a lead 151, which in turn connects with the outputlof vacuum tube V-2 through a capacitor 152 and a resistor 153, Vunder which conditions, the microphone 28 willact 7 as a speaker to reproduce the sound vreceived by the pickup 141. 'Ihe shifting of the switch 89 to the playback position also actuates the switch 89d to disconnect the recording head 45 from the output transformer 150 and also actuates the switch 89o to establish the operating conditions for a warning signal, which `will now be described.

The purpose of this warning signal is to notify the operator of the machine that he should not dictate when the selector switch 89'is in the playback condition, and the pickup arm 15 is in on its rest. This warning signal comprises an audio frequency tone which will be emitted bythe microphone 28, under the conditions just mentioned, if the microphone switch 1'47 is manually closed;

under the mistaken impression that'the machine is ready to take dictation. This audio frequency tone is produced by Va relaxation oscillator which is electrostatically coupled to the input ofthe amplifier circuit associated with the vacuum tubes V-1 and V-2. This oscillator consists of aV gaseous discharge tube N-l, the resistors R-l and R-Z, and the capacitor C-11, connected to the current supplied from vthe rectifier 146.

A connection 154 from the junction between the resistors R-l and R-Z leads to one side of the switch 137 and to a fixed contact of the switch 89C, so that when the Vselector' switch 89 is in theY recording position, the switch 89e will connect the junctions of R-1 and R-2 with the'common connection 142, under which conditions the oscillator circuit will not function. Similarly, if the switch 137 is closed, which will be the case, whenever the pickup arm 15 is olf the cone rest 134, the oscillator circuit will be grounded regardless of the position of the switch 89C, so that no warning signal will occur if the pickup arm is on the disk 16. However, as long as the switchr137 is open Vand the switch 89e is in the playback position, if the microphone switch 147 is closed, a circuit will be established through the resistor R-3 to the common connection, which will cause the gaseous discharge tube N-11 to alternately become conductive and non-conductive, at intervals of time corresponding to some audible frequency. The tube N-1 is physically positioned (as shown in Fig. in close proximity to a portion of the input'circuit of the amplifier, preferably, the control grid or the contact pin leading from the vacuum tube V-l thereto. This electrostatic coupling between the tube N-1 and the grid of the tube V-1 is suicient to produce an audible tone in the microphone 28.

While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not limited to the specic disclosure, but may be modified andembodied in various other equivalent forms without departing from its spirit. VIn short, the invention includes all the modications Yand `embodiments coming within the scope of the following claims.v t Y j/'Having thus fully described vthe invention, what is claimed as new and for'which it is `desired to secure Letters Patent is: 11. In a recording machine for impressing a sound track in a disk recording medium, means to move said recording medium, means to mount a recording headfor linear movement in contact with said recording medium, andto be moved into and out of contact with said medium -to interrupt said recording, a threaded lead screw foradvancing said recording head while in contact uvith said medium, means to rotate said lead screw at a rate proportional -to the movement of said medium including means to restrict Vsaid rotation when said -recording head is out of contact with said medium, a member con'nectedto said recording :head `and engageable with the' thread .of Ysaid lead screw to advance said ref cording head at a rate proportionatertothe speed of Vrotation ofsaid lead screw,said means to restrict rotation of said ylead screw including means to disengagesaid memberfrom said thread for stopping said advancement of Vsaid recording head, Vand also including lost motion means to allow a predetermined amount of angular rotation of said lead` screw of less than one-half a-turn after said disengagement of said member. Y 2. In a traversing mechanism for a phonographic recording head, a lead screw, slipping clutchY means to rotate said screw, means for driving said slipping clutch, positive clutch means, means' to actuate said positive clutch means, and lost motion means connecting said positive clutch means and said lead screw, said positive clutch means being operative when actuated, to'stop said lead screw after aV predetermined amount of rotation of less than one-half turn limited by said lost motion means. f

3. In a traversing mechanism fora recording head, a lead screw, slipping clutch means to rotateV said screw, means to drive said slipping clutch means, a rotatable member, lost motion means connecting said rotatable member with said lead screw, an element Ymovable into and out of clutching engagement with said rotatable member, said rotatable member being operative, when clutched by said movable element, to stop said lead screw after a predetermined amount of rotation of less than one-half turn limited by said lost motion means.

4. In a traversing mechanism for a phonograph recording head, a lead screw having a shaft, slipping clutch means to rotate said screw, means to drive said slipping clutch, a member loosely mounted for rotation on lsaid lead screw shaft, spring means connected between said rotatable member and said lead screw shaft to yieldably urge rotation of said member vwith said shaft, an element movable into clutching engagement with said rotatable member, and stop means to limit the amount of yielding of said spring means, said rotatable member when clutched, being operable to stop said lead screw after a predetermined amount Ihalf turn. f

5. In a mechanism for linearly advancing a recording head, a lead screw, slipping clutch means to drive said lead screw, means to drive said slipping clutch means at a predetermined rate of speed in one direction, means to engage and disengage said recording head and said lead screw, one-way lost motion means connected with said llead screw to advance said lead screw and said recording head at a rate of speed greater than said predetermined rate of speed, and positive clutching means connected with said engaging and disengaging means and said oneway lost motionv means, operative when said recording head is disengaged, to rotate said lscrew by -an amount of less than one-half turn and limited by said lost motion means, and thereafter release said lead -screw when said recording head is engaged.

6. In a mechanism for linearly advancing a recording head, a lead screw, slipping clutch means to drive said lead screw, means to drive said slipping clutch means lat a predetermined rate of speed in one direction, means to engage and disengage said recording head and said lead screw, a toothed member loosely rotatable on said lead screw shaft to the extent of less than one-half turn with respect thereto, stop means to limit relative rotation of said toothed member and said lead screw in one direction, ratchet means engageable with said toothed member t0 rotate said lead screw in said first direction, and a member connected with said engaging and disengaging means for .the recording head to positively engage said toothed member when said recording head is disengaged from said lead screw.

7. In a dictating machine for use with -a combination microphone and sound reproducer having a recording medium movable in one direction, and transducer means to coact with said recording medium movable transversely thereof, lead screw means, means to rotate said lead screw at a rate proportional to the rate of movement of said -of rotation of less than one@ recording medium, electrical amplifier means having input and output connections, switch means having one position to connect said combination microphone and sound reproducer to the input of said amplifier, and a second position to connect said reproducer to the output fof said amplilier, au element connected to said transducer means and movable radially with respect to said lead screw into a first position in engagement with the thread of said lead screw, stop means comprising a ratchet gear mounted on said lead screw and including lost motion means having a first position to permit rotation of said lead screw and a second position to stop said rotation through said lost motion means, and control linkage means to shift said stop means, said transducer element, and said switch means, substantially simultaneously between said .two positions, sound being recorded by said medium in said tirsst position and sound being reproduced therefrom in said second position, said lead screw being advanced a predetermined angular amount of less than one-half turn by said lost motion means when said control linkage means is moved from said rst position to said second position, whereby when said control linkage means is shifted from the second to the rst position, said transducer element will be engaged by a succeeding portion of said lead screw thread of less than one-half turn in advance.

8. In a dictating machine having a combination microphone and sound reproducer, a linearly movable recording medium and a transversely movable -transducer means to coact with said recording medium, a horizontal lead screw, a transducer element movable vertically into and out of engagement with said lead screw to advance said transducer means, electrical amplier means having input and output connections, switch means alternatively movable between two positions to connect said combination microphone and sound reproducer with said input or output connections, a first member pivotally mounted to raise and lower said transducer element, clutch means movable alternatively into and fout of engagement with said lead screw, and pivotal linkage means to connect said clutch means and said switch means with said rst member, whereby when said transducer element is alternatively raised or lowered, said clutch means and said switch means will be respectively alternatively moved.

9. In a dictating machine having a combination microphone and sound reproducer, a linearly movable recording medium, a transversely movable transducer means to coact with said recording medium, a horizontal lead screw, a transducer element movable vertically into and out of engagement with said lead screw to advance said transducer means, electrical amplier means having input and output connections, switch means alternatively movable between two positions to connect said combination microphone and sound reproducer with said input or output connections, a iirst member pivotally mounted on said lead screw shaft to raise and lower said transducer element, a second member slidably mounted on said shaft and movable radially thereof Ito alternatively stop or release rotation of said shaft, means to connect said second member and said switch means for simultaneous alternative movement thereof, and cam means actuated by said lirst member to alternatively actuate said second member.

10. The invention as deiined in claim 9, wherein said clutch means includes a toothed wheel rotatable with said lead screw shaft, said second member having a portion adapted to engage with said teeth.

11. The invention as defined in claim 10, wherein said toothed wheel is yieldably connected with said shaft to permit a predetermined angular displacement thereof when second member is engaged therewith.

12. The invention as defined in claim 9, wherein said means to connect said second member and said switch means comprises a third member, and said cam means comprises a projection provided in one of said three members adapted to engage a slotted portion provided in another of said three members.

13. The invention as dened in claim 12, wherein said third member is movable about a fixed pivot and is pivotally connected with said second member and with said switch means, said connections being spaced from said xed pivot.

14. The invention as defined in claim 13, wherein said pivotal connection between said second and third members is yieldable in one direction to permit said third member to actuate said switch means before second member engages with said toothed wheel.

15. The invention as dened in claim 14, wherein said yieldable connection comprises a slot provided in second member, a pin connected to said third member to be received in said slot, -and spring means to urge said pin towards one end of said slot.

16. In a dictating machine, a chassis, a driving motor, a recording arm having a stylus, an apertured disk record supporting turntable located under said stylus, a vertical spindle for said turntable, means connected to said motor for driving said turntable, a horizontal lead screw having V-threads under said turntable operatively driven from said spindle, said recording arm having a depending member provided with a bottom knife edge for engaging in the V-threads of said lead screw, a bumper carried by said depending member, said lead screw having a face cam at one end having an inclined surface matching the pitch of said lead screw, to be engaged by said bumper to serve as a stop for said bumper when said arm is moved outwardly to starting position, whereby said recording arm will be advanced for recording immediately when said knife edge is lowered into said lead screw.

17. The invention as dened in claim 16, in which said face cam is adjustably secured to said lead screw.

18. In -a dictating machine, a chassis, a driving motor, a recording arm having a stylus, an apertured disk record supporting turntable located under said stylus, said turntable having a central driving spindle, means connected to said motor for driving said turntable, a lead screw beneath said turntable and driven by said spindle, said lead screw having a ratchet wheel loosely mounted thereon and having a lost motion connection therewith, means to stop the rotation of said ratchet wheel when said machine is changed from recording to playback, said lost motion mechanism being operative to allow said lead screw to continue to rotate through a 45 degree angle, after which the rotation of said lead screw will also be stopped.

References Cited in the tile of this patent UNITED STATES PATENTS 2,272,905 Conrad et a1 Feb. 10, 1942 2,528,190 Thayer Oct. 31, 1950 2,553,392 Van Eps May 15, 1951 2,611,620 Runge Sept. 23, 1952 2,685,772 Proctor Aug. 10, 1954 2,756,287 Gregory July 24, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent; Noe. 2952747 september 13 1960 Donald F., Balmer et ele It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Paten-t should read as corrected below.

Column l, line 32g for "the" read w to au; column 2 line 9v for "fragmetnarym read ml fragmentarye column 3 l line 32 for "pelwerltngn read preventlng mg columnnlY llnve 27',I for "this" read n This =m5 column 9I llne l'l"l for v `flrest read first we.

Signed and sealed this llth day of April 1961.

(SEAL) Attest:

. YIDEF? ERNEST W. 5W ARHUR W. CRoCKER Attesting Officer Acting Commissioner of Patents 

